Conventionally, a cup-like container formed by bending sheet material such as paper is known as a cake container for holding poundcake and the like. For example, as shown in FIG. 22, a container body 20 comprises a bottom 21 corresponding to the bottom of a cake and a sidewall 22 protruding from the periphery of the bottom 21. The container body 20 consists of a sheet of material, which is shaped like a cup by press working. A fold 23 is defined on the surface of the material. The bottom 21 and the sidewall 22 are separated by the fold 23 as a boundary. Outer folds 24 and inner folds 25 are defined on the surface of the sidewall 22. The surface of the sidewall 22 is divided into a plurality of bent pieces 26a-26c by the folds 24, 25.
Typically, aluminum foil is used as material for such a container. In this case, once the material is bent at the outer folds 24 and the inner folds 25, bent folds are easy to form. Thus, the folds 24, 25 are difficult to unfold, and the entire configuration of the sidewall 22 in the container body 20 is favorably maintained.
Meanwhile, if the material is made of synthetic resin, paper or the like, a restoring force that restores the material to its original flat shape is applied to the outer folds 24 and the inner folds 25 when the material is bent by press working. This leads to a problem in that the sidewall 22 loses its shape, and the entire configuration of the sidewall 22 cannot be properly maintained.
Accordingly, it is an object of the present invention to provide a container in which the entire configuration of the sidewall in the container body is favorably maintained by making the folds defined on the sidewall not to unfold.